Photosynthetic, biochemical, and ultra-structural changes in the chloroplasts of two ginkgo (Ginkgo biloba L.) cultivars during leaf development
Photosynthetic, biochemical, and ultra-structural changes in the chloroplasts of two ginkgo (Ginkgo biloba L.) cultivars during leaf development
复制标题
两个银杏（Ginkgo biloba L.）品种叶片发育过程中叶绿体的光合、生化和超微结构变化
DOI：
10.1080/14620316.2010.11512675
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发表时间：
2010-01
影响因子：
1.9
通讯作者：
Zhang, Mei-Ping
中科院分区：
文献类型：
--
作者：
Xie, Kai-Bin;Gao, Zhi-Ping;Wei, Xiao-Dong;Chen, Guo-Xiang;Han, Biao;Yang, Xian-Song;Zhang, Mei-Ping
摘要研究了10年雌性银杏叶片叶绿素荧光、叶片生化和超微结构的变化。4月至10月，江苏江都大佛之和七星国。PS II的最大量子效率（Fv / Fm）和潜在光合能力（Fv / Fo）在6月和7月达到峰值，随后下降。叶绿素a和总叶绿素浓度的变化遵循这些模式，而叶绿素b和总类胡萝卜素浓度的变化则不那么明显或没有明显的趋势。电子传递活性（PSⅱ、PSⅰ和全链）的变化规律与叶绿素总含量的变化规律一致，在6月前呈先上升后下降的趋势。光合作用生物化学的变化与叶绿体超微结构的变化有关。最初，叶绿体有紧密堆积的类囊体，具有独特的淀粉粒。然而，随着叶片衰老，叶绿体膜开始降解，类囊体组织混乱，亲锇颗粒数量大量增加。总的来说，两个品种在叶绿素荧光和叶片生化方面只有很小的差异。这些结果表明，银杏叶片在6月份达到了最大的光合能力，此时它们完全展开。随着9月份叶片开始衰老，光合能力下降，而每年这个时候的低温和缺水可能加速了这种下降。衰老可能是叶片主动适应外部环境变化的结果。
Summary Changes in chlorophyll fluorescence, leaf biochemistry, and ultra-structure were studied in 10-year-old female ginkgo trees (Ginkgo biloba L.) cvs. Dafozhi and Qixingguo, from April to October in Jiangdu, Jiangsu Province, P. R. China. The maximum quantum efficiency (Fv / Fm)of PS II and the potential photosynthetic capacity (Fv / Fo) of PS II peaked in June and July, then declined. Changes in the concentrations of chlorophyll a and total chlorophyll followed these patterns, whereas changes in the concentrations of chlorophyll b andtotal carotenoids were less dramatic or had no clear trend. Changes in electron transport activities (PS II, PS I, and the whole chain) followed the same pattern as total chlorophyll content, with increases up until June, then a decline. Changes in the biochemistry of photosynthesis were associated with changes in the ultra-structure of the chloroplasts. Initially, the chloroplasts had tightly-stacked thylakoids with distinctive starch grains. However, as the leaves senesced, the chloroplast membranes began to degrade, the thylakoids became disorganised, and there was a large increase in the number of osmiophilic granules. Overall, there were only small differences in chlorophyll fluorescence and leaf biochemistry between the two cultivars. These results show that ginkgo leaves reached their full photosynthetic capacity in June, when they were fully expanded. Photosynthetic capacity declined as the leaves began to senesce in September, with the decline possibly being accelerated by lower temperatures and water deficits at this time of year. Senescence may be the result of active adaptation by leaves to changes in the external environment.